Indico is a not-framasoft open-source made in CERN event organisation solution : https://getindico.io/

Not sure that the intention is to organise a seminar series...

> main features: > Multi-granular tree-based protection scheme

that will drain users from Facebook instantly! i can already see the flood of people coming. /s

Honestly, to me the main feature is that people tend to upload their slides to indico hosted conferences, but that's more of a cultural feature.

Thanks for the link. This leads us to one proxy of the system's usability, namely the current base of installations: https://instances.joinmobilizon.org/instances

> it's been developped by the fine folks of framasoft

This is enough to tell me it's not gonna be suitable.

Their software are all absolutely awful because their organization follows the skewed principle that FOSS is enough to "sell" and they don't take UX into consideration at all.

Literally none of their alternatives are successful, always for this reason.

Framapad, Framacalc and Framadate are used quite a lot around here.